Fix overriding buffers conditions

[norbertcyran]

What type of PR is this?

/kind bug

What this PR does / why we need it:

When setting buffer condition (ReadyForProvisioning or Provisioning), we overwrite any other condition already set. We should only add/update the condition we're working on. In this PR, instead of overwriting buffer's conditions, we will use meta.SetStatusCondition function from apimachinery that adds or updates the condition. Additionally, I fixed some typos in the conditions.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

I had some issues with circular dependencies when I wrote tests in common_test.go. There was a circular dependency between common and testutil package. I mitigated that by moving out constants from common to the top-level capacitybuffer package (as a side note, I believe that neither testutil nor common deserve their own packages, but let's leave that for now)

Does this PR introduce a user-facing change?

Fixed overwriting CapacityBuffer conditions and fixed typos in condition messages and reasons.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[k8s-ci-robot]

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[k8s-ci-robot]

Hi @norbertcyran. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[norbertcyran]

/assign abdelrahman882 BigDarkClown

[jakubin]

So far a side effect of the bug you're fixing was that when buffer was not ready for provisioning, we also cleared Provisioning flag. Can you double check that having ReadyForProvisioning=False and Provisioning=True won't trigger pod injection?

[k8s-ci-robot]

PR needs rebase.

Details

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